Help!My 5+ year old chicken is spitting or throwing up water?/liquid

I'm hoping someone can tell me what this is? My 5+ yr. old chicken seems to be in distress. She is throwing up water? or liquid of some kind. Her beak is open as if she's having trouble breathing.She was fine today until this evening I noticed her having this trouble while she was up on her roost for the night.She seemed to be making a high pitched sound and I saw liquid coming out of her mouth.I picked her up and was talking to her/massaging her and holding her for a little.Then I put her on the floor area.She walked a few steps & then coughed out liquid it looked like.I spent some more time with her and picked her up and more liquid came out of her mouth.I put her into one of the nesting boxes instead of back on the roost,because I didn't want her to fall off. Can someone tell me what may be going on. I don't want to lose her.She is my helper and keeps me company not to mention,comes in the house to look for me and of course the insides of sunflower seeds or bread crumbs. She is very smart and a good girl..Please help/[1st. time on here...ThanksLB

drooling and crop stasis (which prevents the crop muscles from moving the contents out of the crop through the system) can be due to many things...
might be she drank from a stagnant water source (botulism will cause drooling) or some other problem going on.
Have you felt her crop? does it empty (check for this in the morning) ?